Conventionally, in the production of semiconductor devices, fine processing by lithography using a photoresist has been performed. The fine processing is a processing method for forming fine convexo-concave shapes corresponding to the following pattern on the surface of a substrate by: forming a thin film of a photoresist on a semiconductor substrate such as a silicon wafer; irradiating the resultant thin film with an active ray such as an ultraviolet ray through a mask pattern in which a pattern of a semiconductor device is depicted, developing the film; and subjecting the substrate to etching processing using the resultant photoresist pattern as a protecting film. Recently, however, the high integration of semiconductor devices has progressed and the adopted active ray tends to have a shorter wavelength, such as an ArF excimer laser (193 nm) replacing a KrF excimer laser (248 nm). Following such a tendency, the influence of reflection of an active ray on a semiconductor substrate has been a large issue.
As an underlayer film between the semiconductor substrate and the photoresist, the use of a film known as a hardmask containing a metal element such as silicon and titanium (see, for example Patent Document 1 and Patent Document 2) is performed. In this case, the resist and the hardmask have components largely different from each other, so that the removal rates of the resist and the hardmask by dry etching largely depend on the type of a gas used for dry etching. Then, by appropriately selecting the type of a gas, the hardmask can be removed by dry etching without a large decrease in the film thickness of the photoresist.
Thus, in the production of semiconductor devices in recent years, for achieving various effects such as the reflection preventing effect, a resist underlayer film has become disposed between the semiconductor substrate and the photoresist. Then, also until today, studies of a composition for a resist underlayer film have been performed, however, due to the diversity of characteristics required for the composition and so on, the development of a novel material for the resist underlayer film is desired.
As an EUV lithography method, there is disclosed a method for containing a polymer containing a group including one or more of beryllium, boron, carbon, silicon, zirconium, niobium, and molybdenum in an upper layer of an EUV resist for protecting the EUV resist from pollutant substances or for blocking an undesirable radiation such as UV and DUV (Patent Document 3 and Patent Document 4).